Abstract: Uncompacted location and grouting saturation degree i n the zone of anchorage bar are the two main parameters for judging rock bolts q uality. At present, these two parameters are mainly detected by elastic wave met hod. It is important how to separate the high frequency wavelets from detected i nformation. Wavelet analysis as time -frequency analysis meth od has multi -scale analysis functions and ability of characterizing local features in time domain and frequencies domain. Based on the wavelet multi -resolution research of theoretical model curves and engineering information, the results show that high frequency from different reflection interfaces can be separated in wavelet domain.